will run somecommand every month the 15th day or if the day is a Sunday, at 1 past midnight (00:01).

Real-life Example: Scheduling Drush Updates

Drush and Cron can be used to update Drupal automatically.

First, run the crontab -e command. More info can be found in the previous section.

Next, add the following line to the file:

0 0 * * * cd /path/to/your/drupal/folder/ && drush pm-update

This will execute the cd /path/to/your/drupal/folder/ command, changing the current directory to your drupal folder, and the drush pm-update command, updating Drupal, every day, at midnight. The && indicates a new command follows.